There is always a new diet trend that people are eager to hop aboard but the gluten-free diets seem to be one that possesses staying power. In fact, more people in the U.S. are on gluten-free diets even though the proportion of Americans diagnosed with celiac disease has been steady from 2009 to 2014, NBC News reported Wednesday.

Celiac disease is a disorder in which a person cannot digest gluten properly. Gluten is a protein typically found in bread, rye and barley, known for being a protein that is completely indigestible. Although 1.76 million people have been diagnosed with celiac disease in the U.S., an estimated 2.7 million people in the country have either eliminated or reduced gluten from their diet without being diagnosed, a study found.

Research has determined that there were three particular groups who favored living gluten-free without having a medical obligation to stick to the diet. Younger adults ages 20 to 39 years old, females and non-Hispanic whites made up the majority of the gluten-free lifestyle, The Huffington Post reported Thursday.

People without celiac disease believe that going gluten free is healthy because it encourages the elimination of processed foods, Dr. Daphne Miller of the University of California, San Francisco, wrote in a commentary published with the report in JAMA Internal Medicine.

"Part of what may be driving [a] gluten-free diet trend is simply a belief, fueled by marketing and media, that these foods are healthier," she wrote. "Researchers and clinicians can use this as an opportunity to understand how factors associated with this diet affect a variety of symptoms, including gastrointestinal function, cognition, and overall well-being."